1. Technical Field
The present invention relates to a method for manufacturing metal nanoparticles, more particularly to a method for manufacturing metal nanoparticles with which nanoparticles of single metals, metal alloys, or metal oxides, etc., may be synthesized to a high concentration in a water base using a metal catalyst.
2. Description of the Related Art
Methods of manufacturing metal nanoparticles include chemical synthesis methods, mechanical manufacturing methods, and electrical manufacturing methods. With the mechanical manufacturing methods of using mechanical force for grinding, the inevitable mixing in of impurities makes it difficult to synthesize particles of high purity, and it is impossible to produce uniform particles of nano-level sizes. Also, the electrical manufacturing methods, based on electrolysis, have the drawbacks of long manufacturing time and low concentration and thus low efficiency. The chemical synthesis methods can be divided mainly into vapor phase methods and liquid phase methods. The vapor phase methods of using plasma or mechanical evaporation require expensive equipment, so that liquid phase methods are mainly used, with which uniform particles may be synthesized at low costs.
Methods of manufacturing metal nanoparticles by a liquid phase method may be divided mainly into water-based methods and non-water-based methods.
While the non-water-based method allows uniform particle sizes, the particle sizes are merely of several nanos, so that when synthesizing metal nanoparticles such as copper, etc., other forms of surface treatment, such as an antioxidant coating, are required for preventing oxidation.
On the other hand, with the water-based method, the particle distribution is relatively large, but since the size of the particles are several tens of nanos to begin with, the oxidation speed is very slow compared to the non-water-based method. Thus, there is no need for special antioxidant treatment as in the case of the non-water-based method.
However, with the water-based method, it is difficult to synthesize metal nanoparticles to a high concentration. High-concentration synthesis is important in synthesizing nanoparticles, because the higher the concentration to which the nanoparticles are synthesized, the greater the amount of nanoparticles obtained per batch, which allows low costs and less waste, to enable environment-friendly processes and efficient mass production.
Thus, there is a demand for research on new methods of synthesizing nanoparticles to a high concentration using a water-based method.